diff --git a/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix b/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix
index 458e313a3f75..329bd329dc15 100644
--- a/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix
+++ b/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix
@@ -87,19 +87,19 @@ in
   boot.initrd.availableKernelModules =
     [ "mvsdio" "reiserfs" "ext3" "ums-cypress" "rtc_mv" "ext4" ];
 
-  boot.postBootCommands =
+  boot.postBootCommands = lib.mkIf (!boot.initrd.systemd.enable)
     ''
       mkdir -p /mnt
 
       cp ${dummyConfiguration} /etc/nixos/configuration.nix
     '';
 
-  boot.initrd.extraUtilsCommands =
+  boot.initrd.extraUtilsCommands = lib.mkIf (!boot.initrd.systemd.enable)
     ''
       copy_bin_and_libs ${pkgs.util-linux}/sbin/hwclock
     '';
 
-  boot.initrd.postDeviceCommands =
+  boot.initrd.postDeviceCommands = lib.mkIf (!boot.initrd.systemd.enable)
     ''
       hwclock -s
     '';
diff --git a/nixos/modules/tasks/bcache.nix b/nixos/modules/tasks/bcache.nix
index 41fb7664f3d1..0a13522de11f 100644
--- a/nixos/modules/tasks/bcache.nix
+++ b/nixos/modules/tasks/bcache.nix
@@ -1,13 +1,23 @@
-{ pkgs, ... }:
+{ config, lib, pkgs, ... }:
 
 {
+  options.boot.initrd.services.bcache.enable = (lib.mkEnableOption "bcache support in the initrd") // {
+    visible = false; # only works with systemd stage 1
+  };
 
-  environment.systemPackages = [ pkgs.bcache-tools ];
+  config = {
 
-  services.udev.packages = [ pkgs.bcache-tools ];
+    environment.systemPackages = [ pkgs.bcache-tools ];
 
-  boot.initrd.extraUdevRulesCommands = ''
-    cp -v ${pkgs.bcache-tools}/lib/udev/rules.d/*.rules $out/
-  '';
+    services.udev.packages = [ pkgs.bcache-tools ];
 
+    boot.initrd.extraUdevRulesCommands = lib.mkIf (!config.boot.initrd.systemd.enable) ''
+      cp -v ${pkgs.bcache-tools}/lib/udev/rules.d/*.rules $out/
+    '';
+
+    boot.initrd.services.udev = lib.mkIf config.boot.initrd.services.bcache.enable {
+      packages = [ pkgs.bcache-tools ];
+      binPackages = [ pkgs.bcache-tools ];
+    };
+  };
 }
diff --git a/nixos/modules/tasks/filesystems/btrfs.nix b/nixos/modules/tasks/filesystems/btrfs.nix
index ae1dab5b8d8d..b7ebc37dd5cf 100644
--- a/nixos/modules/tasks/filesystems/btrfs.nix
+++ b/nixos/modules/tasks/filesystems/btrfs.nix
@@ -66,19 +66,19 @@ in
         ]
       );
 
-      boot.initrd.extraUtilsCommands = mkIf inInitrd
+      boot.initrd.extraUtilsCommands = mkIf (inInitrd && !config.boot.initrd.systemd.enable)
       ''
         copy_bin_and_libs ${pkgs.btrfs-progs}/bin/btrfs
         ln -sv btrfs $out/bin/btrfsck
         ln -sv btrfsck $out/bin/fsck.btrfs
       '';
 
-      boot.initrd.extraUtilsCommandsTest = mkIf inInitrd
+      boot.initrd.extraUtilsCommandsTest = mkIf (inInitrd && !config.boot.initrd.systemd.enable)
       ''
         $out/bin/btrfs --version
       '';
 
-      boot.initrd.postDeviceCommands = mkIf inInitrd
+      boot.initrd.postDeviceCommands = mkIf (inInitrd && !config.boot.initrd.systemd.enable)
       ''
         btrfs device scan
       '';
diff --git a/nixos/modules/tasks/filesystems/cifs.nix b/nixos/modules/tasks/filesystems/cifs.nix
index 47ba0c03c563..0de292a69208 100644
--- a/nixos/modules/tasks/filesystems/cifs.nix
+++ b/nixos/modules/tasks/filesystems/cifs.nix
@@ -16,7 +16,7 @@ in
     boot.initrd.availableKernelModules = mkIf inInitrd
       [ "cifs" "nls_utf8" "hmac" "md4" "ecb" "des_generic" "sha256" ];
 
-    boot.initrd.extraUtilsCommands = mkIf inInitrd
+    boot.initrd.extraUtilsCommands = mkIf (inInitrd && !config.boot.initrd.systemd.enable)
       ''
         copy_bin_and_libs ${pkgs.cifs-utils}/sbin/mount.cifs
       '';
diff --git a/nixos/modules/tasks/filesystems/ext.nix b/nixos/modules/tasks/filesystems/ext.nix
index a14a3ac38549..9b61f21643ab 100644
--- a/nixos/modules/tasks/filesystems/ext.nix
+++ b/nixos/modules/tasks/filesystems/ext.nix
@@ -1,14 +1,20 @@
-{ pkgs, ... }:
+{ config, lib, pkgs, ... }:
+
+let
+
+  inInitrd = lib.any (fs: fs == "ext2" || fs == "ext3" || fs == "ext4") config.boot.initrd.supportedFilesystems;
+
+in
 
 {
   config = {
 
-    system.fsPackages = [ pkgs.e2fsprogs ];
+    system.fsPackages = lib.mkIf (config.boot.initrd.systemd.enable -> inInitrd) [ pkgs.e2fsprogs ];
 
     # As of kernel 4.3, there is no separate ext3 driver (they're also handled by ext4.ko)
-    boot.initrd.availableKernelModules = [ "ext2" "ext4" ];
+    boot.initrd.availableKernelModules = lib.mkIf (config.boot.initrd.systemd.enable -> inInitrd) [ "ext2" "ext4" ];
 
-    boot.initrd.extraUtilsCommands =
+    boot.initrd.extraUtilsCommands = lib.mkIf (!config.boot.initrd.systemd.enable)
       ''
         # Copy e2fsck and friends.
         copy_bin_and_libs ${pkgs.e2fsprogs}/sbin/e2fsck
diff --git a/nixos/modules/tasks/filesystems/f2fs.nix b/nixos/modules/tasks/filesystems/f2fs.nix
index a305235979a2..1d52861aa39d 100644
--- a/nixos/modules/tasks/filesystems/f2fs.nix
+++ b/nixos/modules/tasks/filesystems/f2fs.nix
@@ -13,7 +13,7 @@ in
 
     boot.initrd.availableKernelModules = mkIf inInitrd [ "f2fs" "crc32" ];
 
-    boot.initrd.extraUtilsCommands = mkIf inInitrd ''
+    boot.initrd.extraUtilsCommands = mkIf (inInitrd && !config.boot.initrd.systemd.enable) ''
       copy_bin_and_libs ${pkgs.f2fs-tools}/sbin/fsck.f2fs
       ${optionalString (any (fs: fs.autoResize) fileSystems) ''
         # We need f2fs-tools' tools to resize filesystems
diff --git a/nixos/modules/tasks/filesystems/jfs.nix b/nixos/modules/tasks/filesystems/jfs.nix
index fc3905c7dc20..700f05af2bec 100644
--- a/nixos/modules/tasks/filesystems/jfs.nix
+++ b/nixos/modules/tasks/filesystems/jfs.nix
@@ -12,7 +12,7 @@ in
 
     boot.initrd.kernelModules = mkIf inInitrd [ "jfs" ];
 
-    boot.initrd.extraUtilsCommands = mkIf inInitrd ''
+    boot.initrd.extraUtilsCommands = mkIf (inInitrd && !boot.initrd.systemd.enable) ''
       copy_bin_and_libs ${pkgs.jfsutils}/sbin/fsck.jfs
     '';
   };
diff --git a/nixos/modules/tasks/filesystems/reiserfs.nix b/nixos/modules/tasks/filesystems/reiserfs.nix
index ab4c43e2ab82..7b017a83db84 100644
--- a/nixos/modules/tasks/filesystems/reiserfs.nix
+++ b/nixos/modules/tasks/filesystems/reiserfs.nix
@@ -15,7 +15,7 @@ in
 
     boot.initrd.kernelModules = mkIf inInitrd [ "reiserfs" ];
 
-    boot.initrd.extraUtilsCommands = mkIf inInitrd
+    boot.initrd.extraUtilsCommands = mkIf (inInitrd && !config.boot.initrd.systemd.enable)
       ''
         copy_bin_and_libs ${pkgs.reiserfsprogs}/sbin/reiserfsck
         ln -s reiserfsck $out/bin/fsck.reiserfs
diff --git a/nixos/modules/tasks/filesystems/unionfs-fuse.nix b/nixos/modules/tasks/filesystems/unionfs-fuse.nix
index f54f3559c341..f9954b5182f9 100644
--- a/nixos/modules/tasks/filesystems/unionfs-fuse.nix
+++ b/nixos/modules/tasks/filesystems/unionfs-fuse.nix
@@ -6,7 +6,7 @@
     (lib.mkIf (lib.any (fs: fs == "unionfs-fuse") config.boot.initrd.supportedFilesystems) {
       boot.initrd.kernelModules = [ "fuse" ];
 
-      boot.initrd.extraUtilsCommands = ''
+      boot.initrd.extraUtilsCommands = lib.mkIf (!config.boot.initrd.systemd.enable) ''
         copy_bin_and_libs ${pkgs.fuse}/sbin/mount.fuse
         copy_bin_and_libs ${pkgs.unionfs-fuse}/bin/unionfs
         substitute ${pkgs.unionfs-fuse}/sbin/mount.unionfs-fuse $out/bin/mount.unionfs-fuse \
@@ -16,12 +16,23 @@
         chmod +x $out/bin/mount.unionfs-fuse
       '';
 
-      boot.initrd.postDeviceCommands = ''
+      boot.initrd.postDeviceCommands = lib.mkIf (!config.boot.initrd.systemd.enable) ''
           # Hacky!!! fuse hard-codes the path to mount
           mkdir -p /nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-${pkgs.util-linux.name}-bin/bin
           ln -s $(which mount) /nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-${pkgs.util-linux.name}-bin/bin
           ln -s $(which umount) /nix/store/eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee-${pkgs.util-linux.name}-bin/bin
         '';
+
+      boot.initrd.systemd.extraBin = {
+        "mount.fuse" = "${pkgs.fuse}/bin/mount.fuse";
+        "unionfs" = "${pkgs.unionfs-fuse}/bin/unionfs";
+        "mount.unionfs-fuse" = pkgs.runCommand "mount.unionfs-fuse" {} ''
+          substitute ${pkgs.unionfs-fuse}/sbin/mount.unionfs-fuse $out \
+            --replace '${pkgs.bash}/bin/bash' /bin/sh \
+            --replace '${pkgs.fuse}/sbin' /bin \
+            --replace '${pkgs.unionfs-fuse}/bin' /bin
+        '';
+      };
     })
 
     (lib.mkIf (lib.any (fs: fs == "unionfs-fuse") config.boot.supportedFilesystems) {
diff --git a/nixos/modules/tasks/filesystems/vfat.nix b/nixos/modules/tasks/filesystems/vfat.nix
index 958e27ae8a32..5baab1c802cf 100644
--- a/nixos/modules/tasks/filesystems/vfat.nix
+++ b/nixos/modules/tasks/filesystems/vfat.nix
@@ -15,7 +15,7 @@ in
 
     boot.initrd.kernelModules = mkIf inInitrd [ "vfat" "nls_cp437" "nls_iso8859-1" ];
 
-    boot.initrd.extraUtilsCommands = mkIf inInitrd
+    boot.initrd.extraUtilsCommands = mkIf (inInitrd && !config.boot.initrd.systemd.enable)
       ''
         copy_bin_and_libs ${pkgs.dosfstools}/sbin/dosfsck
         ln -sv dosfsck $out/bin/fsck.vfat
diff --git a/nixos/modules/tasks/filesystems/xfs.nix b/nixos/modules/tasks/filesystems/xfs.nix
index 98038701ca58..80e46efcc780 100644
--- a/nixos/modules/tasks/filesystems/xfs.nix
+++ b/nixos/modules/tasks/filesystems/xfs.nix
@@ -15,14 +15,14 @@ in
 
     boot.initrd.availableKernelModules = mkIf inInitrd [ "xfs" "crc32c" ];
 
-    boot.initrd.extraUtilsCommands = mkIf inInitrd
+    boot.initrd.extraUtilsCommands = mkIf (inInitrd && !boot.initrd.systemd.enable)
       ''
         copy_bin_and_libs ${pkgs.xfsprogs.bin}/bin/fsck.xfs
         copy_bin_and_libs ${pkgs.xfsprogs.bin}/bin/xfs_repair
       '';
 
     # Trick just to set 'sh' after the extraUtils nuke-refs.
-    boot.initrd.extraUtilsCommandsTest = mkIf inInitrd
+    boot.initrd.extraUtilsCommandsTest = mkIf (inInitrd && !boot.initrd.systemd.enable)
       ''
         sed -i -e 's,^#!.*,#!'$out/bin/sh, $out/bin/fsck.xfs
       '';
diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 5158bc681e08..ad426fcf4e0a 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -524,6 +524,7 @@ in
   systemd-confinement = handleTest ./systemd-confinement.nix {};
   systemd-cryptenroll = handleTest ./systemd-cryptenroll.nix {};
   systemd-escaping = handleTest ./systemd-escaping.nix {};
+  systemd-initrd-btrfs-raid = handleTest ./systemd-initrd-btrfs-raid.nix {};
   systemd-initrd-luks-keyfile = handleTest ./systemd-initrd-luks-keyfile.nix {};
   systemd-initrd-luks-password = handleTest ./systemd-initrd-luks-password.nix {};
   systemd-initrd-shutdown = handleTest ./systemd-shutdown.nix { systemdStage1 = true; };
diff --git a/nixos/tests/systemd-initrd-btrfs-raid.nix b/nixos/tests/systemd-initrd-btrfs-raid.nix
new file mode 100644
index 000000000000..40fd2d4dc611
--- /dev/null
+++ b/nixos/tests/systemd-initrd-btrfs-raid.nix
@@ -0,0 +1,45 @@
+import ./make-test-python.nix ({ lib, pkgs, ... }: {
+  name = "systemd-initrd-btrfs-raid";
+
+  nodes.machine = { pkgs, ... }: {
+    # Use systemd-boot
+    virtualisation = {
+      emptyDiskImages = [ 512 512 ];
+      useBootLoader = true;
+      useEFIBoot = true;
+    };
+    boot.loader.systemd-boot.enable = true;
+    boot.loader.efi.canTouchEfiVariables = true;
+
+    environment.systemPackages = with pkgs; [ btrfs-progs ];
+    boot.initrd.systemd = {
+      enable = true;
+      emergencyAccess = true;
+    };
+
+    specialisation.boot-btrfs-raid.configuration = {
+      fileSystems = lib.mkVMOverride {
+        "/".fsType = lib.mkForce "btrfs";
+      };
+      virtualisation.bootDevice = "/dev/vdc";
+    };
+  };
+
+  testScript = ''
+    # Create RAID
+    machine.succeed("mkfs.btrfs -d raid0 /dev/vdc /dev/vdd")
+    machine.succeed("mkdir -p /mnt && mount /dev/vdc /mnt && echo hello > /mnt/test && umount /mnt")
+
+    # Boot from the RAID
+    machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-btrfs-raid.conf")
+    machine.succeed("sync")
+    machine.crash()
+    machine.wait_for_unit("multi-user.target")
+
+    # Ensure we have successfully booted from the RAID
+    assert "(initrd)" in machine.succeed("systemd-analyze")  # booted with systemd in stage 1
+    assert "/dev/vdc on / type btrfs" in machine.succeed("mount")
+    assert "hello" in machine.succeed("cat /test")
+    assert "Total devices 2" in machine.succeed("btrfs filesystem show")
+  '';
+})